from typing import Any, Optional


class JsonSchema:
    def __init__(self, json_schema: dict, namespace: str = "base"):
        self.schema = json_schema
        self.namespace = namespace
        self._parsed_objects = set()

    def to_avro(self) -> dict:
        return self._get_avro_type_and_call(self.schema)

    def _get_avro_type_and_call(
        self,
        schema: dict,
        name: Optional[str] = None,
        required: bool = True,
        namespace: Optional[str] = None,
    ) -> dict:
        type_field = schema.get("type")
        default = schema.get("default")
        if type_field == "object":
            if "properties" in schema:
                result = self._json_object_to_avro_record(schema, namespace)
            else:
                result = self._json_dict_to_avro_map(name, schema)
        elif "$ref" in schema:
            result = self._json_ref_to_avro_record(name, schema, namespace)
        elif type_field == "array":
            result = self._json_array_to_avro_array(name, schema)
        # elif "enum" in schema:
        #     if type_field == "string":
        #         result = self._json_enum_to_avro_enum(name, schema)
        #     else:
        #         raise TypeError(
        #             f"{name} Cannot have Enum of type {type_field}. Enums must be strings"
        #         )
        elif "anyOf" in schema:
            result = self._json_anyof_to_avro_union(name, schema)
        elif "allOf" in schema:
            raise TypeError(
                "Avro schema cannot have nested objects with default values."
            )
        elif type_field == "string":
            if schema.get("format") == "binary":
                result = self._json_primitive_type_to_avro_field(name, "bytes", default)
            else:
                result = self._json_primitive_type_to_avro_field(
                    name, "string", default
                )
        elif type_field == "integer":
            result = self._json_primitive_type_to_avro_field(name, "long", default)
        elif type_field == "number":
            result = self._json_primitive_type_to_avro_field(name, "double", default)
        else:
            raise TypeError(f"Unknown type.")
        if default is None and not required:
            result.update({"type": ["null", result["type"]], "default": None})
        return result

    def _json_object_to_avro_record(
        self, json_object: dict, namespace: Optional[str] = None
    ) -> dict:
        required_field = json_object.get("required", [])
        title = json_object["title"]
        if namespace is None:
            namespace = self.namespace
        record_namespace = f"{namespace}.{title}"
        if record_namespace in self._parsed_objects:
            return {"type": "record", "name": record_namespace}
        else:
            self._parsed_objects.add(record_namespace)
            result = {
                "namespace": namespace,
                "name": title,
                "type": "record",
                "fields": [
                    self._get_avro_type_and_call(
                        property_data,
                        property_name,
                        property_name in required_field,
                        record_namespace,
                    )
                    for property_name, property_data in json_object[
                        "properties"
                    ].items()
                ],
            }
            if "description" in json_object:
                result["doc"] = json_object["description"]
            return result

    def _json_dict_to_avro_map(self, name: str, schema: dict):
        result = {"name": name} if name is not None else {}
        result["type"] = {
            "type": "map",
            "values": self._get_avro_type_and_call(schema["additionalProperties"]),
        }
        return result

    def _json_primitive_type_to_avro_field(
        self, name: Optional[str], object_type: str, default: Optional[Any] = None
    ) -> dict:
        result = {"name": name} if name is not None else {}
        if default is None:
            result["type"] = object_type
        else:
            result.update({"type": object_type, "default": default})
        return result

    def _json_array_to_avro_array(self, name: str, schema: dict):
        result = {"name": name} if name is not None else {}
        result["type"] = {
            "type": "array",
            "items": self._get_avro_type_and_call(schema["items"]),
        }
        return result

    def _json_enum_to_avro_enum(self, name: str, schema: dict):
        result = {
            "name": schema["title"],
            "type": "enum",
            "symbols": schema["enum"],
        }
        if "description" in schema:
            result["doc"] = schema["description"]
        return result

    def _json_anyof_to_avro_union(self, name: Optional[str], schema: dict):
        result = {"name": name} if name is not None else {}
        result["type"] = [
            self._get_avro_type_and_call(item) for item in schema["anyOf"]
        ]
        return result

    def _json_ref_to_avro_record(
        self, name: str, schema: dict, namespace: Optional[str] = None
    ):
        selected_schema = self._find(schema["$ref"])
        if name is not None:
            return {"name": name, "type": self._get_avro_type_and_call(selected_schema)}
        else:
            return self._get_avro_type_and_call(selected_schema)

    def _find(self, reference: str):
        ref_list = reference.split("/")
        selector = self.schema
        if ref_list[0] == "#":
            for specifier in ref_list[1:]:
                selector = selector[specifier]
            return selector
        else:
            raise TypeError(f"Wont resolve {ref_list[0]}")
